Counterweight mechanism for oil well pumps



y 3935 J. c. SLONNEGER 2,023,554

COUNTERWEIGHT MECHANISM FOR OIL WELL PUMPS Filed May 4, 1934 INVENTOR go1421. 6 J/Zmwgar Patented Dec. 10, 1935 UNITED STATES PATENT OFFICECOUNTERWEIGHT MECHANISM FOR OIL WELL PUMPS 4 Claims.

This invention relates to oil well pumps of the reciprocating type andmore particularly to counterweight mechanism therefor.

Oil well pumps of the reciprocating type are ordinarily actuated by acrank operated walking beam counterweighted to counteract the loadimposed by the long string of pump rods which extend to the pump at thebottom of the well.

As heretofore arranged, such systems set up objectionable periodicforces which react upon the driving mechanism and the pump rods toproduce objectionable noise, premature wear, and rod breakage. Iattribute this objectionable condition tothe fact that the counterweightis ordinarily connected to the walking beam to reciprocate in unisontherewith, so that the counterweight thus constitutes in effect anintegral part of the reciprocating pump-driving system, and its mass,thus combined with that of the system, increases to an objectionabledegree those inertia forces which result from the reciprocating motion.

This objectionable condition is aggravated by the resiliency of thereciprocating pump-driving system, and particularly the pump rods, andby inevitable slaclmess between the rotating driving crank and thereciprocating system as heretofore arranged.

An object of the present invention is to provide a counterweight forsystems of this type so arranged as to avoid the objectionable reactionsheretofore experienced. This I have accomplished by connecting thecounterweight to the rotating crank in a manner to impart to thecounterweight a reciprocating motion independently of and. preferablydifferent from that of the reciprocating pump-driving system, so thatthe counterweight does not constitute a part of the latter. 7

A more specific object is to so arrange the parts that the opposedforces resulting from the counterweight and pump rod loads are utilizedto maintain all connections taut throughout each reciprocating cycle.

Other objects and advantages will appear, expressed or implied, from thefollowing description of an illustrative embodiment of this invention.

The single figure oi the accompanying drawing shows a reciprocating pumprig equipped with a counterweight arranged in accordance with thepresent invention.

The pump operating mechanism shown includes a conventional walking beaml rockably supported intermediate its ends upon the usual Sampson postl. The usual string of pump rods is supported and actuated in a wellknown manner from that end of the beam not shown, and the other end l2of the beam is actuated through a conventional link l3 from the pin M ofa rotat- 5 ing crank l5. The beam it], link l3, and pump rods (notshown), constitute conventional parts of the usual reciprocatingpump-driving system and need no further description.

The rotating crank I5 is also a conventional 1 part of a standard pumprig and in this instance is shown supported and actuated by a speedreducer unit l6 driven from any appropriate power source.

In this instance a counterweight l l is provided,

arranged to counteract the weight of the pump rods but in such manner asto avoid the objectionable periodic reactions heretofore experienced.

I have discovered several ways by which this can be accomplished, butthe arrangement shown has proven entirely satisfactory. Thecounterweight is supported by the crank I5 independently of thereciprocating pump-driving system.

It is shown connected to the crank through a link 20 suspended from thecrank pin M. In this instance the link 20 is connected to a lever l8 towhich the counterweight is attached and by Which the latter is guidedduring reciprocation imparted to it by the crank. The lever I 8 is shownfulcrumed upon a horizontally offset pivot pin [9.

It will be noted that with the parts thus arranged, the motion of thecounterweight I1 is different in kind from that of the walking beam II];that is to say, the rate of acceleration and deceleration of thecounterweight is different from that of the walking beam atcorresponding points in their operating cycles. For instance, thewalking beam attains a maximum velocity during travel of the crank pinHi through a point in an upper quadrant of its circular path P, whereasthe counterweight attains a maximum velocity during travel of the crankpin through a point in a lower quadrant of that path, and as the crankI5 passes downwardly through the horizontal position shown, thecounterweight is accelerating while the walking beam is decelerating.

The counterweight thus forms a part-of a reciprocating system having areciprocating motion different in kind from that of the pump actuatingsystem, and yet the weight of the counterweight system always reacts ina manner to counteract the pump rod load.

It will be noted that the counterweight is connected to the pumpreciprocating system through the rotating driver, both links 20 and I 3being independently connected to the pin l4 constituting a part of therotating crank. The link 20, under the counterweight load, always pullsdownwardly upon the pin l4 throughout crank rotation, while the link l3,under the pump rod load, always pulls'upwardly on the pin. With such anarrangement noslack can ever develop between the crank and the drivenlinks.

Various changes may be made in the embodiment of the inventionhereinabove specifically described without departing from or sacrificingthe advantages of the invention as defined in the appended claims.

I claim:-

1. In an oil well pumping mechanism the combination of a rotary driver,a reciprocating pump rod actuator including a walking beam, areciprocating counterweight, motion transmitting means connecting saidrotary driver with said actuator, and separate motion transmitting meansdirectly connecting said rotary driver with said counterweight andthrough which said counterweight reacts on said driver to oppose thepump rod load.

2. In an oil well pumping mechanism the combination of a rotary driver,a reciprocating walking beam, a reciprocating counterweight,reciprocating means directly connected with said rotary driver forreciprocating said walking beam, and separate reciprocating meansdirectly connected with said rotary driver for reciprocating saidcounterweight.

3. In an oil Well pumping mechanism the combination of arotary driver, areciprocating pump rod actuator including a walking beam, areciprocating counterweight, a link directly connected with said rotarydriver for reciprocating said walking beam, and a separate link directlyconnected with said rotary driver for reciprocating said counterweight.

4. In an oil well pumping mechanism the combination of a rotary driver,a reciprocating pump 20 rod actuator including a walking beam, acounterweight lever, a link directly connected with said rotary driverfor actuating said actuator, and a separate link directly connected withsaid rotary driver for reciprocating said lever.

JOHN C. SLONNEGER.

